Prior art techniques for adding D2 encoded PCM samples require conversion of the eight bit D2 encoded PCM sample into a thirteen bit linear coded sample. These samples are then added or subtracted, depending upon their respective sign bits, and the resultant value is then reconverted to an eight bit D2 encoded number.
The present invention discloses a novel arrangement for performing numerical operations directly on the D2 encoded PCM samples without the requirement of first converting them to linear code and then reconverting the results of the numerical operation back to D2 code. Under the present invention, the D2 encoded PCM samples are interpreted to be in the form of floating point numbers. After the numerical operations have been performed the resultant number is normalized to account for an implied magnitude bit.